MISC: switch line returns back to unix

Shame on me for messing up line returns. This diff will make history
ugly. Sorry
BUG: restore setup.py clean functionality

Proper implementation of the clean command.
MISC: fix rst
Updated with more explanatory text. Also changed to use train_test_split function
Corrected some typos, and added more explanation for the precision recall example.
Clarified a few wordy sentences
Attempted a clearer explanation of precision-recall score
Adjusted to fit 80 character columns, and corrected definition of precision
Removed random_seed argument to svm.SVC
Added contributions to whats_new
Further expansion of the precision_recall curve explanation, spelling corrections, and general cleanup.
Added random_state argument to svm.SVC
Added links to cross_val_score, auc_score, and recall_score
Added link to precision_score
Updated whats_new and fixed a typo in plot_precision_recall.py
WEBSITE add yhat testimonial